Diffuser for a centrifugal compressor

Abstract

An improved diffuser ( 10 ) for a centrifugal compressor which comprises blading with blades ( 12 ).

1 . Improved diffuser ( 10 ) for a centrifugal compressor, characterised in that it comprises blading with blades ( 12 ).  
     
     
         2 . Improved diffuser ( 10 ) according to  claim 1 , characterised in that the said blading has a strength s of the said blades ( 12 ) which is between 0.5 and 1, including extreme values, the said strength s being provided by the ratio between the pitch p of the said blading and the chord c of the said blades ( 12 ), the said pitch p being provided by the ratio  
       
         
           
             
               
                 
                   π 
                   · 
                   Dp_in 
                 
                 Z 
               
               , 
             
           
           
           
               
           
         
       
       wherein Z is the number of the said blades ( 12 ) and Dp in is the diameter of an intake edge of the said blading.  
     
     
         3 . Improved diffuser ( 10 ) according to  claim 1  or  claim 2 , characterised in that a deflection β of the said blading, i.e. the angle of displacement of a tangent line at the outlet of the blade ( 12 ) relative to a tangent line at the intake of the blade ( 12 ), is between an angle of 0° and an angle of 10°, including extreme values.  
     
     
         4 . Improved diffuser ( 10 ) according to  claim 1  or  claim 2  or  claim 3 , characterised in that the ratio between a diameter of an intake edge Dp in of the said blading and an outer diameter of an impeller D 2  of the said centrifugal compressor, is between 1.04 and 1.14, including extreme values.  
     
     
         5 . Improved diffuser ( 10 ) according to  claim 1  or  claim 2  or  claim 3  or  claim 4 , characterised in that the ratio between a diameter of an outlet edge Dp out of the said blading and an outer diameter of an impeller D 2  of the said centrifugal compressor, is between 1.25 and 1.35, including extreme values.  
     
     
         6 . Improved diffuser ( 10 ) according to  claim 1  or  claim 2  or  claim 3  or  claim 4  or  claim 5 , characterised in that it is used in centrifugal compressor stages with a coefficient of flow of 0.03 or less.  
     
     
         7 . Improved diffuser ( 10 ) according to  claim 1 , characterised in that a design of the said blades ( 12 ) is optimised by means of the so-called CFD i.e. Computational Fluid Dynamic method (in other words a method for fluid-dynamics calculation).  
     
     
         8 . Improved diffuser ( 10 ) according to  claim 1 , characterised in that a design of the said blades ( 12 ) is optimised by means of experimental methodology.  
     
     
         9 . Improved diffuser ( 10 ) according to  claim 1 , characterised in that it is used for delivery of a centrifugal compressor for re-injection.  
     
     
         10 . Improved diffuser ( 10 ) for a centrifugal compressor, substantially as described and illustrated and for the purposes specified.